Tapping-die.



Patented Feb. 23, 1909.

f having face-threads for tapping in the usual UNITED srn r gs PATENTOFFICE.

GEORGE ERMOLD, OF ELIZA Bli'lll, NEW JERSEY.

TAPPING-DIE To all whom it may concern:

Be it known that l, GEORGE ERMOLD, a citizen of the United States,residing in Elizabeth, in the county of Union and State of New Jersey,have invented certain new and useful Improvements in 'lapoing-Dics, ofwhich the following is a speci ication.

This invention relates to certain improve- I ments in tapping-dies bywl'iich rods, tubes and similar articles can be quickly provided withscrew-threads, and more especially to certain improvements on thetapping-die for which Letters Patent were granted to Sven Tidernan onNovember 25, 1890, No.441,603, for an improved die and die-stock.

The object of this invention is to furnish an improved tapping-die whichcan be readily adjusted to the diameter of the article to be threadedwithout liability of breaking, and which is firmly held within the stockafter being inserted therein and adjusted to the required size of thearticle to be threaded; and for this purpose the invention consists inthe novel features to be hereinafter described and claimed.

In the accompanying drawings, Figure 1 represents a plan-view of myimproved tapping-die, shown as inserted into the stock with which it isto be used, Fig. 2 is a side-elevation of the die shown as detached fromthe stock, Fig. 3 is an enlarged vertical section of Fig. 2, and Fig. 4is a detail side-view of one of the pivot-pins of the tapping-die.

Similar letters of reference indicate corresponding parts throughout theseveral figures.

Referring to the drawin s, a, a a represent the three sections of w ichmy improved tapping-die is com osed. The die-sections are made ofsector-s ape, each of the sections 0 a being pivoted to the section a bypivotconnections which consist of two plain pivotpins 6 that areinterposed between the sections and seated in semi-circular recesses at1 each end of the jaw a and in corresponding recesses at the adjacentends of the sections a, 0

The inner portions of the sections a, a a are provided with projectingportions or aws l l 1 l l l manner. Between the outer ends of thesections and the inner ends or jaws of the same are arrangedclearance-openings 6. At the adjacent ends of the die-sections a a op 0-site to the pivot-connections 0f the same with l Patented Feb. 28, 1909.

Serial No. 423,823.

l located in the stock and which has an inner tapering end, saidset-screw being arranged in t e circular portion of the stock as shownin Fig. l. VWicn tie jaws of tie tappingdies are adjusted to therequired size, tee circular portion of the stock is tightly applied tothe die by means of a clamping-screw g, which enters into a socket-hole0 in the circumference of the die-section a. diametrically to theset-screw g, and two additional clamping-screws g which pass through thestock one for each of the (1 (L The tapping die is now in position to beapplied to the article to be tapped in the usual manner. Thedie-sections are provided at their outer edges with grooves 7H, and thepivot-pins are provided in line with the grooves 71 with annular grooves71 About the die-sections is placed. a flat spring-ring h which isgrooved centrally in order to form a rib which is seated in the groovesof the die-sections and pivot-pins. The outer groove in the springringit by which the rib on the inner face is formed serves, in connectionwith the clamping-screws g for positioning the die-sections in thestock, the inner ends of said screws engaging in said groove, as shownin Fig. 1. The spring-ring h l: as also a hole 0 registering with thehole 0 in the circumference of the die-section for the inner pointed endof the clampingscrew g The sections of the improved tapping-die are madefrom a solid steel rod by cutting ofi' solid circular blanks of the sizeof the tappin -die. The solid blank is then provided wit l a centralopening, and. adjacent thereto with the clearance openings 6. Adjacentto the clearance-openings are arranged the recesses for the pivo t-pins.After this the blank is split, in radial direction into threediesections. Then the circumferential grooves are cut into thedie-sections and pivotpins and the die-sections and pins connected bythe spring-ring, the opening between the ends of which being located atthe point Where the tapering end of the set-screw q i; intended to enterinto tl e slit between t'r-e die-section; d, u. 'lrc tapping-die licingmade up from t .c lilanlw in: hardened in tnc usual manner.

llpc inlvantag'm of my improved tappingdie are, first, t at ti e namei-i alwaffe rcndy [or usfl and not lialilc to ln'ealt'ao'e or splitting;eccond, tE-at :irlielm of dlll'crcnt diametern \vlt un certain limit;can he tapped by lllL eanie owing to ti e facility by Wnici": t? c jawscan. he adjnr-ted to tire article to be t =readedt t ird. twat owing totire adjustaliility of t e die to dill'erent diameters a smaller numberof tapping-dies it, required tlmn heretofore; fourth, twat anydie-section can be readily replaced in case t e tLread on its jaw a?ould become injured by accident or wear, tie (llO-SOFIlUlI's being; madeup ready for nee and readily axrembled by mean of tr e epringningconnection, and laetl), t at ti e spring-ring and eeta rcrewe l' old thediesectionu and pivot-pini in tacir exact pontion and prevent any partof ti 0 die from moving independently of t e otnere, making the diethereby as rigid an a SUlid tapj'iing die made of one piece.

Having time described my invention, I claim as new and (.lesire toser'rnre by Letters Patent:

1. A tapping-die comprising three sectorenaped die-sectionew, eachsection having a F groove at it outer part, a tapping-jaw at its l inncrpart and clear:nice-(1pmrings adjacent mid jar-r, pivot-pin; intcrpomdlwtwcen one of tr e diczcctio1r1 and t e two adjaecnt die- Heetio'nw,waid pi\-'ot-- in:--1 being provided with annular groovce, and :1mpring-rilrg' provided wit a central Q'roovc forming a I'll) seated in te grooves of tr c diexcctione and pivotpins.

2. The combination, with a tapping-die colnpri ing die-nm-tions ravinggroovce at ti eir outer part; pivot-pine interpoeed between said ecctionand provided with annular grooves, and a spring-ring: Haring a groove atits outer face lm'nling a ril) extending into ti e grooves of thedier-.ectione and pivot-pine, of a stock for the ttli)j)i1lf-(ll0, awet-wrow nter ine through the etocl; between certain of tiredie-wctione, a clainping wwrew pasting through the stock intosocket-holes of the hPI'lIlLIJ'lILg and die-sections, and setserew';pruning tilrougn tin: stock into the groove on tlo outer face of tl'Cepring-ring. In testimony, that 1 cl aim the foregoing as I myinvention, I have signed my name in presence of two subscribingWltHELSGS.

GEORGE ERMOLD.

Witnesses.

PAUL G EPEL, j HENRY J. SUI-IRBIER.

